Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2017 May 2;773:66–90. doi: 10.1016/j.mrrev.2017.05.001

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© 2017 Elsevier B.V. All rights reserved.

Since January 2020 Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID-19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre - including this research content - immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active.

PMC Copyright notice

Fig. 8 — Schematic representation for LCR Based DNAzyme–Fluorescein Chemiluminescence Resonance Energy Transfer technique.

A) Perfect match; Four probes are used in this assay (colored/shaded differently). Two probes are identical to the upstream and the downstream sequences for the SNP site while the other two probes are complementary to the upstream and the downstream sequences for the SNP site. The 3′ end for one of the complementary probes is biotinylated (indicated by letter B) while the 5′ end for the other complementary probe is labeled with fluorescein (indicated by letter F). The 3′ end for one of the identical probes has G-quadruplex sequence (colored in grey) while the 5′ end for the other identical probe is unlabeled. At 50 °C, the biotin and the fluorescein labeled complementary probes hybridize adjacently on target DNA and are then sealed (indicated by small black box) by ligase enzyme whereas the duplex formed between complementary and identical probes (four probes) is not sealed. The mixture is then allowed to hybridize following denaturation at 90 °C. The ligated product (with a small black box) is then used as a new template for the ligation of both the unlabelled probe and the G-quadruple containing probe. Exponential amplification of ligated products is achieved through subsequent cycles. All biotinylated products (with letter B) are then immobilized on streptavidin-coated magnetic particles (SA-MPs) (indicated by large grey circle) while all non-biotinylated products are removed during magnetic separation process. G-quadruplex containing biotinylated duplex intercalates hemin (indicated by small black circle) forming peroxidase-mimicking DNAzyme that catalyzes chemiluminiscence energy transfer from luminal-H₂O₂ to fluorescein (indicated by letter F). B) Mismatch; Since there is no hybridization with target DNA, no ligation occurs and only the biotinylated (indicated by letter B) complementary probe binds SA-MPs (indicated by large grey circle). The latter does not contain the G-quadruplex which is essential to generate the CRET signal.